McCartan has been a long-term target for the Glens with Ballymena United trying hard to keep their prize asset.
But it seems there has been a breakthrough in negotiations with reports of an Irish League record transfer fee of well in excess of £60,000 being agreed between the clubs.
McCartan, who netted 21 goals for the Sky Blues last season following his return from English football, only recently signed a two year contract with the Braidmen until 2023.
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However, after the Glens reportedly submitted recent offers, which were described at derisory by United, it seems the 27-year-old is on the brink of a move to The Oval.
And McCartan looks set to be joined in east Belfast by Bobby Burns, who has left Barrow by mutual consent.
Burns was on loan with Mick McDermott's side last season before suffering a season-ending leg break last October.
He remained with the club during his rehabilitation and now looks likely to sign a permanent deal with the Glens.
This double capture will be a huge boost to the Ovalmen ahead of the new campaign.